Long-nosed fur seal dies from H5 bird flu in South Australia, first mainland mammal case

A long‑nose fur seal was discovered dead on the sands of Beachport, South Australia, on Wednesday, marking the first confirmed case of the H5 subtype of avian influenza in a mammal on the Australian mainland. The death comes amid a growing wave of outbreaks that has already claimed more than 1,000 greater crested terns on offshore islands, as reported by Premier Peter Malinauskas. The seal’s demise is seen as a further indication that the virus is spreading beyond its initial avian hosts.

Federal agriculture minister Julie Collins described the seal’s death as “not unexpected” as the disease continues to move through the country. The incident follows the Premier’s announcement of three mass mortality events on islands along the Limestone Coast, underscoring the escalating reach of the virus across both marine and terrestrial ecosystems. Authorities are monitoring the situation closely and have increased surveillance of wildlife populations in the region.

The finding signals a significant shift in the epidemiology of H5 bird flu, raising concerns about potential wider impacts on wildlife and public health. Continued vigilance and rapid response measures will be essential to contain the outbreak and protect vulnerable species across Australia.